my $engines = join(",",map($dbh->quote($_), @choices));
my $sql = <<EOF;
  SELECT engine, name1, name2, name3, name4, lable1, lable2, lable3, lable4, settings1, settings2,
                  settings3, settings4
  FROM special_fields
  WHERE engine IN ( $engines )
    AND (
       settings1="public" OR settings2="public" OR settings3="public" OR settings4="public"
  )
EOF